Prince William once told the Queen he had second thoughts about Kate Middleton

Prince William and Kate Middleton have been married for eleven years (yes, it really has been over a decade since the world watched them say 'I do' at Westminster Abbey), but the couple had dated for around nine years before walking down the aisle.

The now Duke and Duchess of Cambridge met while at St Andrews University, and while they were friends for a time they soon started dating and officially became an item.

While one royal expert has claimed that 'nobody expected' the pair to go the distance once they graduated, William and Kate proved everyone wrong and are happily married with three children, Prince George, Princess Charlotte and Prince Louis.

However, it wasn't always smooth sailing for the royal couple. In 2007, with pressure mounting on the Prince to propose to Kate, the Cambridges split briefly.

According to royal expert Katie Nicholl, William started to question his future with Kate when they were both 25 years old, and the Duke became so anxious about the relationship that during the Christmas period of 2006 he spoke to the Queen and his father, Prince Charles, about what to do.

She told The Mirror: 'William had been having second thoughts and sat down with his father and his grandmother to have a frank discussion about his future with Kate.

'Both advised him not to hurry into anything.'

Just a few months later, William called time on their relationship - something which Kate has later spoken about, stating she 'wasn't very happy about it' - and they took a break.

It is said that during this time, the royals realised that Kate was 'a no-brainer' and the break-up actually cemented her role as future Queen with palace insiders impressed by how she handled herself with the media during those difficult months.

After a trip to the Seychelles a little while later, William and Kate made a 'marriage pact' and the rest - as they say - is history!